This is a continuation of our “Hormone Free” Foods post that introduced dietary estrogen and phytoestrogens. Today we will focus on how dietary phytoestrogens in soy can positively impact men’s health.
Men often hear that they need avoid soy products, such as tofu and tempeh. This is idea is false, but is based on the estrogen like compounds and the fear that it will negatively affect testosterone levels in men, often referred to as “adverse estrogenic effects”. For example, the common belief that soy will lead to all sorts of things, including “man-boobs” and lower testosterone.
Find your way around:
Phytoestrogens: Part 3 of 3
Have you read part 1 of this topic? “Hormone Free” Foods will give you an introduction into Estrogens and Phytoestrogens. In addition to how they function differently and the importance of fiber in reducing excess estrogen.
The Science of hormones
Let’s take a look at what hormones are before we get straight into the topic at hand. A hormone is any substance created by the body that circulates throughout the blood.
This image shows the structure of Testosterone. Don’t worry if this image doesn’t make any sense. It is here as a reference.
Eating Soy products will decrease testosterone
This is a myth that was supported by a 2007 study showing a 19% decrease in serum testosterone levels following soy protein isolate supplementation (Effect of Soy Protein on Testosterone Levels). As a result, many people thought that ingesting soy products would decrease testosterone. However, later meta-analyses showed that this was not the case. Indeed, the addition of these products to men’s diet had no negative effect on testosterone levels. It was later revealed that the original paper’s author based his idea on a single individual, rather than looking at the entire study group.
This is another example that when looking at scientific literature we should go with the best available balance of evidence. Within the field of research, it is important to follow the money. When in doubt of the conclusions, check the funding source to identify if there is any incentive for finding specific results due to industry funding.
A study out of the UK found: “Testosterone levels were unchanged and there was a substantial improvement in glycaemia and cardiovascular risk markers with SPI compared with SP alone over 3 months.”
Testosterone and health
This showed that the men consuming soy products had no changes in testosterone levels. Instead there was significant improvement in type 2 diabetes management and cardiovascular health markers over 3 months.
Another article studying isoflavones from soy concluded that “no feminizing effects could be found among 9 clinical controlled trials” (Soybean isoflavone exposure does not have feminizing effects on men).
Man boobs…Oh My!
The only 2 known cases in the scientific literature of men developing feminizing effects from soy (Exploring the Soyfood Controversy). These men were eating 14-20 servings of soy per day! That is 9 times higher than the typical Japanese intake. So eating 1-3 servings per day will not cause feminizing effects.
But the big guy at my gym said…
Men want to maintain and build muscle through resistance training. It is tempting to take the advice of someone at the gym as the truth. However, knowledge gained in the laboratory will always trump “bro-science”.
Soy protein supplementation does not affect men’s sex hormones. A study compared soy protein versus whey protein in untrained college age men. Neither protein significantly affected either testosterone nor estrogen in the subjects (Soy protein supplementation in college-aged men). Soy protein supplementation will not adversely affect resistance training effects.
Plant-based professional body builder Nimai Delgado (Muscle and Fitness)
Benefits of Soy for Men
Soy and Prostate Cancer
In a recent study, men who ate the highest amounts of soy had a reduction of 26% lower risk of prostate cancer. How this works is the outer cells (epithelium) of prostate have the “B” Estrogen receptor. The phytoestrogens from soy can bind to these and turn off growth, reducing the overall risk of cancer.
Dr. Dean Ornish and a group of researchers put men with prostate cancer into an intensive lifestyle change program. The men that followed the program saw a decrease in prostate specific antigen (PSA) levels. PSA levels are a common test that Doctors use to monitor progression. Higher amounts indicate the cancer is growing, while lower mean it’s stable or shrinking. After a blood draw, serum from these men inhibited the growth of prostate cancer cells 8 times more than from the control group!
Soy and fertility
Currently soy exhibits no known effect on male fertility due to the presence of phytoestrogens. Contrary to popular belief, consuming soy products will not turn men into “sissies”. Actually consuming dairy may be the real culprit considering it has actual estrogen.
Plants supply 20-40% testosterone and contain high levels of hormone building blocks.
What about Dairy Milk?
Cow’s milk naturally contains hormones. Dairy milk consumption increases exposure to hormones (e.g. Estrogen & Progesterone). The hormones in milk are designed to grow a baby cow from 60lbs to 600lbs in 6 months. Progesterone hormone is concentrated when milk is made into butter and cheese.
What effect does this have on male fertility? As much as 60-80% of ingested female sex hormones come from milk and milk products. So to improve your hormone balance, put down the milk products and pick up the soy products.
The graph below shows men’s estrogen levels before (white bars) and after (black bars) having dairy milk.
If that is what dairy milk does to adults, then what is it doing to our children? That question was addressed by the same researchers and they found the following results. This second graph shows how estrogen levels in children are also raised after having dairy milk.
Both graphs show that after having dairy milk, estrogen levels rise in the body for men and children. This means that, if you follow the USDA guidelines and have three glasses of milk a day, your estrogen levels will rise significantly three times a day. Of course this is not normal and we recommend to avoid dairy products for all men, women and children.
Insulin-Like Growth Factor (IGF-1)
During the normal growing process, our bodies produce a hormone called IGF-1. This at moderate levels is what helps children go through the natural stages of development including growth spurts. However, once you are an adult, you no longer need to grow taller and these levels should be naturally low. High levels at the wrong stage in development can lead to cancer growth or progression.
There is evidence that soy products at normal consumption levels (3 servings/day) reduces IGF-1 levels in the body, resulting in decreased cancer development. Dairy products have been linked to increased IGF-1 which result in higher rates of cancer development and progression.
What about the children? Since this hormone mimics insulin, excess IGF-1 from dairy products has been linked to both Type I diabetes and pre-adolescent puberty. This is a result of the levels consumed through food being on top of what the body naturally produces.
What about genetically modified soy?
What is Glyphosate?
Glyphosate is the trademark name for a phosphonic acid compound. The acid is corrosive and toxic to human, plant, and aquatic life.
More specifically, glyphosate causes serious eye damage, and is toxic to aquatic life with long lasting effects. Glyphosate is a registered trademark of the Monsanto Corporation.
Glyphosate in Soy
Let’s dive into why traces of glyphosate are found in soy. First, most of the soy grown in the US genetically modified. This process allows the plant to withstand heavy pesticide application, such as glyphosate. This is known as “RoundUp-Ready Soy”. As a result, GMO soy has less crops lost to pests and grows quickly with modern intensive farming practices.
Why worry Glyphosate in Soy?
This GMO soy is good for the bottom-line of Monsanto, but not optimal for human health. Glyphosate is linked to numerous diseases, including Asthma, Arthritis, Kidney disease, and Obesity, to name a few (Glyphosate). Glyphosate disrupts human hormones, and is linked to low sperm count in men (Oligospermia).
Luckily, there is another option. Opt for organic soy if possible, but don’t avoid soy if you can’t afford the non-GMO. Glyphosate is not only found in non-GMO soy products, as many know it as the product RoundUp.
Final Thoughts
Soy has been unfairly given a bad reputation for too long. This is partly due to old science, and partly due to industry-driven public misinformation campaigns. The current balance of evidence shows that soy is beneficial for young children and adults. Also, there is evidence linking increased soy consumption to decreased risk of developing, and slowing progression of prostate cancer in men. Men should fear soy no longer. Instead make the switch to soy products over dairy products, for improved athletic performance and longer, healthier lives.
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